Golf putting devices having a selectively variable surface are well known. Numerous kinds of means for selectively varying the surface of these devices have been developed over the years. For example, U.S. Pat. No. 1,761,039 issued to Hazeltine and U.S. Pat. No. 3,727,917 issued to MacLean disclose variable contour golf putting devices with hinged panels and pegs for propping up various sections of the putting surface at the hinge joints; U.S. Pat. No. 3,690,673 issued to Occhipinti and U.S. Pat. No. 3,892,412 issued to Koo disclose variable contour golf putting devices with inflatable air sacs disposed at various locations under the putting surface; U.S. Pat. No. 1,582,183 issued to Maurer, U.S. Pat. No. 3,170,694 issued to Dolce, U.S. Pat. No. 4,222,568 issued to Russo and U.S. Pat. No. 4,790,538 issued to Gettelfinger disclose variable putting surfaces using a variety of gears, shafts, cams and levers to distort the putting surface; U.S. Pat. No. 3,595,581 issued to Andersen, U.S. Pat. No. 3,658,343 issued to Rogers and U.S. Pat. No. 4,247,112 issued to Del Raso disclose variable putting surfaces using a series of jacks to prop up various sections of the putting surface; U.S. Pat. No. 2,118,084 issued to Heinzelmann, U.S. Pat. No. 2,334,540 issued to Buffham, U.S. Pat. No. 3,601,407 issued to Lorrance, U.S. Pat. No. 4,743,027 issued to Simjian, U.S. Pat. No. 5,002,280 issued to Hines and U.S. Pat. No. 5,172,914 issued to Primerano disclose variable putting surfaces which use a variety of levers and rods to push up on the underside of the putting surfaces; U.S. Pat. No. 3,871,661 issued to Korff which discloses a kidney shaped putting green under which an angled panel is swiveled to raise portions of the putting green; and U.S. Pat. No. 4,240,637 issued to Cross which discloses a coin operated putting apparatus which is tilted using a crank shaft which communicates with a threaded bolt around which a nut affixed to the putting surface is rotated thus increasing or decreasing the elevation of the putting surface. However, these designs for varying the contour of the putting surface are unwieldy, require numerous interlocking parts and are costly to manufacture and assemble. In contrast, there are a few relatively simple designs which are known. For example, U.S. Pat. No. 5,318,303 issued to Kim discloses a hinged putting surface and a canopy from which strings with hooks are hung to selectively engage and hold up the panels; U.S. Pat. No. 3,508,756 issued to Bedford discloses a flexible horizontal putting surface, suspended by loops under tension between vertical arms, which is contoured by raising and lowering the loops on the arms causing the surface to torque; and U.S. Pat. No. 4,211,417 issued to Brown and U.S. Pat. No. 4,988,106 issued to Coonrod disclose a putting surface which is contoured by pushing a wedge-shaped device under the bottom of the putting surface. However, these simplistic designs do not provide the user with potential surface variations adequate to recreate actual putting conditions encountered on the golfing green.
U.S. Pat. No. 5,855,522, the disclosure of which is hereby incorporated by reference, discloses a variable golf putting surface which the present invention improves over.